Fabricators have various tools available to them. With the right tools, you can turn pieces of scrap metal into just about anything your mind can conjure. Most metal fabrication requires tools for cutting and joining pieces, although some tools can pull double duty in a pinch.
When working with metal, two tools most often stand out as must-haves: the plasma cutter and the MIG welder. What are their uses? And which one would help the most with the jobs you do? We break down everything you need to know below.
What is a Plasma Cutter?
As the name suggests, a plasma cutter is a device that cuts through metal using plasma. Its torch emits a high-pressure gas stream, such as hydrogen or oxygen. An electric current runs from the torch nozzle to the cutting surface. As the charge runs through the gas, it changes its natural state from a gas to plasma, a superhot state between liquid and gas.
The jet of plasma created by the torch burns at about 25,000 degrees Celsius. At these extreme temperatures, a plasma cutter doesn’t melt the metal. It entirely obliterates the material, leaving it in two pieces. An additional air stream is blown around the plasma jet. The stream blows any debris – or dross – away from the cut edge, keeping it clean.
What is a MIG Welder?
There are many types of welders, including arc welders, MIG welders, and TIG welders. They all do the same thing: join two pieces of metal. But they accomplish it in different ways.
MIG stands for metal inert gas. A MIG welder functions by passing an electrical current (or arc) into an electrode between two pieces of metal. As this happens, the metal melts and forms a join or weld.
MIG welding is a sub-class of processes that have been in use since the 1940s, called gas metal arc welding (GMAW for short). It is one of the most popular and simple forms of welding, often cited as being easy to learn and perform.
An electrode wire feeds through the end of the welding gun, or torch, into the welding pool. The arc’s positive charge passes through it, superheating and melting it in place. Like with plasma cutting, an air jet is blown around the welding arc to protect the weld pool from the debris and atmospheric gases that will weaken the weld.
Why do I Need Both a Plasma Cutter and a Mig Welder?
The most obvious difference between a plasma cutter and a MIG welder is their core use. The cutter is used to cut metal, while the welder joins it. In both cases, the cutting material is metal.. Neither tool will work effectively on any other material.
Are MIG Welders and Plasma Cutters Easy to Set Up?
Plasma cutters have a simple setup process that makes them easily transportable. All they require is a pair of gas tanks and a power source. Once these things are connected, the tool is ready to use.
By contrast, MIG welders (and others) require a degree of tuning for their arc jets. This must be set and tested rigorously before each use and will vary from job to job.
What Quality Should I Expect in the Finished Product?
Welds are rough by nature. The melting and sealing of a joint is a slow and imprecise art, resulting in an obvious seam where the work occurred. The result can be cleaned by sanding the weld down, but ultimately the join will always be visible.
The plasma jet from a plasma cutter is significantly neater. The extreme heat of the arc obliterates all the metal it touches, resulting in a cleaner and smoother cut.
Are MIG Welders and Plasma Cutters Based on the Same Technology?
Welding has been around since about 1948, and its simplicity belies that. The art of heating an electrode to join two pieces of metal is rudimentary compared to a plasma cutter.
Plasma-cutting technology has been around since the 80s and has seen many advancements in nozzle design and gas usage since then. Computer Numerical Control or CNC plasma cutters add programmability and more user controls, making them powerful metal working tools.
What Are the Uses of a Plasma Cutter?
While plasma cutters offer a range of potential uses, this range is limited. For example, the plasma arc is extremely hot but only powerful enough to cut through to a certain thickness. Handheld plasma cutters are typically used for cutting metals up to 1½ inches thick, while machine-operated cutters only go as thick as six inches.
Since plasma cutters use an electric current, the surface of the cutting metal must be conductive. If the current cannot connect with the cutting surface, then the plasma cannot form. This means plasma cutters are limited to cutting:
- Stainless steel
However, plasma cutters are extremely portable and can be used effectively at any angle. This makes them great for use onsite anywhere there is a power source.
What are the Uses of a MIG Welder?
MIG welders are extremely versatile when it comes to welding. They are one of the most common tools found in any workshop. Since their functionality only requires an electrode rod to melt between two metals, they can work on almost anything.
This wide functionality means MIG welders are often used to:
- Repair cars, bikes, and other vehicles
- Build or repair framework for buildings
- Repair solid structures
Note that MIG welders can be used as cutters, provided the cutting doesn’t require the precision offered by plasma cutters. You can quickly modify them for specific cuts. Rather than using the arc to melt an electrode, the arc can heat and cut with alterations. This should be done by someone with the correct know-how, however.
Choosing whether to purchase a plasma cutter or a MIG welder depends on which tasks you need to complete. Anything that requires joining needs a welder, and cutting needs a cutter. However, the two tools can work together to form an amazing toolkit for many jobs.